Machine readable code combining preprinted indicia with hand-mark data

ABSTRACT

A method of entering a hand-marked response into a system by altering a predetermined modified bar code symbol in a manner so that the bar code is rendered readable. In this manner, bar code reading devices can be utilized to detect the hand-marked response. In an alternative embodiment, one of several potential responses may be marked and rendered non-decodable. A bar code reading device determines which of the several responses has been hand-marked by ascertaining which is non-decodable. Marking the response sheets may be aided by using an opaque template sheet or using a pressure sensitive overlay sheet.

FIELD OF THE INVENTION

This invention relates to reading systems for reading bar codes andhand-mark information and particularly, to a system and method forcombining preprinting indicia with user-generated handmark informationto form a machine readable document which can be read by a bar codereading system.

BACKGROUND OF THE INVENTION

Bar code reading systems for reading preprinted bar codes are well knownand are used in many diverse applications, such as, for example,shipping, manufacturing, and retail checkout applications. The bar codereading systems are generally arranged to read one or more of theindustry standard bar code formats, such as, for example, Code 39,Interleaved 2 of 5, Discrete 2 of 5, Code 128, Code 93, Codebar, UPC,etc. A bar code reading system reads and decodes the bar codes and formsa digital representation of the data which can then be displayed and/orprovided to a host computer for subsequent processing.

The industry standard bar codes are generally encoded and pre-printed onan item (i.e., pre-printed bar code on a grocery item) or are encodedand machine printed on an adhesive label using a printer. SymbolTechnologies Inc. portable printer Model No. PS1000 is illustrative of aprinter for encoding and printing industry standard bar code labels.

Hand-mark sense system are also known which read hand-mark senseinformation from a document. A common example of a document usinghand-mark sense information is a multiple choice examination, where theuser darkens predetermined areas on the document corresponding to thedesired answer to a question. A hand-mark sense reader then detects thevarious darkened areas on the document, and based on the relativeposition of the darkened areas on the document, information describingthe hand-mark sense information is formed. To determine the relativeposition of the darkened areas on the document the hand-mark sensereader must accurately feed or position the document relative to thereader. Accordingly, variations in the size and shape of the documentare limited. Finally, it is noted that a hand-mark sense reader isentirely different than a bar code reader, is not capable of reading barcodes, and generally costs more to produce than bar code readers.

There are many applications in which it is desired to combine bothpre-printed bar code symbols with user enterable data (hand-mark senseinformation) on the same document. U.S. Pat. No. 4,877,948 describes asystem for reading a document which contains both pre-printed bar codesand hand-mark sense information. In the U.S. Pat. No. 4,877,948, fixedinformation, which can not be modified by the user, is encoded andpre-printed as bar codes. The hand-mark sense information is entered bythe user in an area on the document different from where the bar codesare printed. A reading device comprising in combination a bar codescanning device and a hand-mark sense reading device is arranged to readthe bar code and the hand-mark sense information, respectively, and toform information descriptive thereof. However, as can be appreciated,the manufactured cost for the combination reader is inherently greaterthan the manufactured cost of just the bar code scanning device.

U.S. Pat. No. 4,728,784 discloses a method and system for reading handmodified bar codes. The reading device of the U.S. Pat. No. 4,728,784 isarranged to read a unique preprinted bar code having a portion thereofhand-modified by a user. The hand-modified bar code is then scannedusing a bar code reader and decoded by a unique decoding algorithm whichdetects which portion of-the unique preprinted bar code has beenhand-modified. Based upon the position of the hand-mark within thepre-printed bar code, a predetermined character is output by the readingdevice. However, it is noted that the encoding format of the data isentirely different than the industry standard formats. Accordingly, barcode readers that are arranged to decode bar codes encoded in theindustry standard formats can not be used for decoding the bar codesdescribed in the U.S. Pat. No. 4,728,784.

SUMMARY OF THE INVENTION

It is an object of the present invention to develop a method and systemfor reading a document having both pre-printed bar codes and hand-marksense information printed thereon that overcomes the limitations of theprior art.

It is a further object of the present invention to develop a method andsystem for reading a document having both pre-printed bar codeinformation and hand-mark sense information thereon using a bar codereader which is arranged to read and decode industry standard bar codeformats.

According to one embodiment of the invention, a method of entering ahand-marked response into a system is provided using a plurality ofencoded and pre-printed bar code sequences, where each bar code sequencecorresponds to a unique predetermined character string and includes aplurality of spaces and a plurality of bars and a modified bar. Themodified bar is arranged to render the bar code sequence non-decodableby a bar code decoding device when the modified bar is not hand-marked,where the modified bar is arranged to render the bar code sequencedecodable by the bar code decoding device when the modified bar ishand-marked. The method comprises the step of hand-marking the modifiedbar of a selected one of the plurality of bar code sequences. Theplurality of bar code sequences are read by a bar code reading means anda first signal representative of the plurality of bar code sequences isformed. The the first signal is processed by the bar code decodingdevice to decode the unique predetermined character string correspondingto the selected one of the plurality of bar code sequences whichincludes the hand-marked modified bar, and forming a second signalincluding the decoded unique predetermined character string of theselected one of the plurality of bar code sequences. The second signalis then output from the bar code decoding device to the system.

BRIEF DESCRIPTION OF THE DRAWINGS

The features believed characteristic of the invention are set forth inthe appended claims. The invention itself, however, as well as otherfeatures and advantages thereof, may best be understood by reference tothe detailed description of a specific embodiment which follows, whenread in conjunction with the accompanying drawings, wherein:

FIG. 1 illustrates a bar code reading system according to a preferredembodiment of the present invention;

FIG. 2 shows in greater detail the document to be read by the bar codereading system of FIG. 1;

FIG. 3 shows in greater detail the preprinted bar code sequencesrepresenting the ITEM selection segment of FIG. 2;

FIG. 4 is a flow-chart illustrating the operation of the host computerof FIG. 1;

FIG. 5 shows a document to be read by the bar code reader in a furtherembodiment of the present invention;

FIG. 6 shows in greater detail the preprinted bar code sequencesrepresenting the MULTIPLE CHOICE #1 selection segment of FIG. 5;

FIG. 7a shows in greater detail a bar code character of the bar codesequence of FIG. 6 in accordance with an embodiment of the presentinvention;

FIG. 7b shows in greater detail the character of FIG. 7a in standardCode 39 format;

FIG. 8 shows a document to be read by the bar code reader of FIG. 1 inaccordance with a further embodiment of the present invention;

FIGS. 9a-9b shows a document to be read by the bar code reader of FIG. 1in accordance with a further embodiment of the present invention;

FIGS. 10-11 illustrate a bar code sequence to be read by the bar codereader of FIG. 1 in accordance with a still further embodiment of thepresent invention;

FIGS. 12-13 illustrate a bar code sequence to be read by the bar codereader of FIG. 1 in accordance with a yet another embodiment of thepresent invention;

FIG. 14 illustrates a bar code sequence to be read by the bar codereader of FIG. 1 in accordance with a yet another embodiment of thepresent invention; and

FIGS. 15-16 are flowcharts illustrating the operation of the decodemodule of FIG. 1 when decoding the bar code sequence of FIG. 14.

DETAILED DESCRIPTION OF A SPECIFIC EMBODIMENT

A number of specific embodiments of the invention are described herein.It will be understood that these embodiments are presented for thepurpose ofillustration and not as limiting the scope of the invention.

Referring to FIG. 1, a bar code reading system 1 is shown for reading adocument 2 which includes fixed, pre-printed bar code information aswell as variable hand-mark information. The bar code reading system 1includes a bar code reader 3 for scanning selected portions of thedocument. Various types of desk-top or portable, hand-held scannersystems are exemplified by U.S. Pat. Nos. 4,369,361; 4,387,297; and4,409,470 -- all of such patents being owned by the assignee of theinstant invention and being incorporated by reference herein. The reader3 outputs a digitized signal which is representative of the scannedportion of the document.

A decode module 4 receives the digitized signal generated in the reader3, and determines whether the digitized signal represents a bar codeconforming to one of many industry standard formats for which the decodemodule 4 is programmed to decode. Assuming that the digitized signalgenerated in the reader 3 does conform to one of the industry standardformats for which the decode module 4 is programmed to decode, thedecode module 4 calculates the desired data, e.g., the multiple digitrepresentation or code of the bar code symbol, in accordance with analgorithm contained in a software program. Symbol Technologies, Inc.Product No. LL500 is an illustrative example of the decode module 4shown in FIG. 1.

Upon a successful decode of a bar code, the decode module 4 communicatestoa host computer 5 the decoded data, e.g., the representation or codeof thebar code symbol. The host computer 5 utilizes the decoded data invaried ways depending upon application software resident in the hostcomputer.

FIG. 2 illustrates the document 2 of FIG. 1 in greater detail. Forillustrative purposes, bar codes conforming to the Code 39 standard areshown with the understanding that the present invention is not limitedthereto. In this embodiment, the document 2 is shown as an order formfor ordering from a mail order catalog service. The document 2 containsfixed,pre-printed bar code information describing the customer name 6and address7A-B. It is noted that in accordance with the Code 39 format,each line of the bar code begins and ends with a start/stop character"*". When the reader 3 scans the bar code 6 representing the customer'sname, a digitized signal representative of the bar code 6 is output tothe decodermodule 4. The decoder module 4 decodes the digitized signaland outputs decoded data representing the characters positioned betweenthe start/stopcharacters "*" to the host computer 5 . For example, whenbar code 6 is scanned, the decode module 4 generates the decoded data"JANE SMITH" whichis then provided to the host computer 5. Similarly,when bar code 7A is scanned, the decode module 4 generates the decodeddata "2 MAIN STREET" and when bar code 7B is scanned, the decode module4 generates the decodeddata "TOWN NY 12345".

A user ordering section 8 is provided in which the customer selects anITEMfor purchase, along with the desired COLOR and SIZE for the selecteditem. The ITEM selection segment 9 includes three pre-printed bar codesequences9A-9C. The ITEM selection segment 9 is shown in greater detailin FIG. 3.

Referring to FIG. 3, the first preprinted bar code sequence 9A in theITEM selection segment 9 includes wide and narrow bars and spacesarranged to form a character string. The first character 11 representedby the bar code sequence 9A is a start/stop character "*"; the secondcharacter 12 represented by the bar code sequence 9A is a "P"; and thethird character 13 represented by the bar code sequence 9A is thestart/stop character "*". All the bars (narrow and wide) in the bar codesequence 9A are printed as solid black, with the exception of one bar,which is herein referred to as the invisible bar 10A (also referredherein as the modifiedbar), which is printed in red ink. The invisiblebar 10A is shown in FIGS. 2 and 3 for illustrative purposes as a hashedbox. In the case where the reader 3 is a laser scanner which scans thesymbols with a red laser light, the red printin of the invisible bar 10Areflects the red laser light, and therefore, the invisible bar 10A cannot be distinguished from the white background, and therefore, is notdetected by the reader 3. However, the red color of the invisible bar10A can be seen by a human.

The remaining bar code sequences 9B and 9C are similar to bar codesequence9A in that they each start and end with start/stop characters"*". In bar code sequences 9B-9C the middle characters 14 and 15 are "P"and "D" respectively. The middle characters 14 and 15 each includes aninvisible bar 10B and 10C, respectively, which is not detected by thereader 3.

The item selection line 9, as initially pre-printed, is intentionallyarrange to cause the decoding module 4 to fail to decode characters 12,14and 15. In more detail, the decoding module 4 is arranged to outputdecodeddata to the host computer 5 only when the decode module 4 decodesa bar code sequence having proper start/stop characters and when eachcharacter between the start/stop characters are determined to be validcharacters. However, since the characters 12, 14 and 15 containinvisible bars 10A, 10B and 10C, respectively, which are not detected bythe reader 3, the digitized signal output by the reader 3 is notrepresentative of valid characters. Accordingly, the decoding module 4fails to detect a valid barcode sequence from the digitized signaloutput by the reader 3.

Color selection line 19 and size selection line 20 are similar to itemselection line 9 in that each includes a number of bar code sequences,each sequence beginning and ending with start/stop characters. Each barcode sequence also includes a character having one invisible bar (e.g.,color selection line 19 has invisible bars 17A-17D and size selectionline20 has invisible bars 18A-18E).

Referring to FIG. 2, to select an item for purchase, a user darkens(e.g., variable hand-mark information), with a number two pencil, aselected one of the invisible bars 10A, 10B or 10C. For example, if theuser wants to select pants for purchase, the user darkens the invisiblebar 10B which ispositioned over the PANTS inscription 16B. To select thedesired color for the pants, the user darkens a selected one of theinvisible bars 17A-17D, each of which corresponds to particular color.Finally, to select a size for the pants, the user darkens one of theinvisible bars 18A-18E, each ofwhich corresponds to a particular size.

After the user completes the entry of the hand-mark information in theuserordering section 8 of the document 2, the document is in conditionto be scanned. A bar code reader 3 scans the fixed, preprinted bar code6 representing the customer's name and a digitized signal representativeof the bar code 6 is output to the decoder module 4. The decoder module4 decodes the digitized signal and outputs to the host computer 5 thecustomers name (e.g., "JANE SMITH"). Similarly, when the fixed,preprintedbar code 7A is scanned, the decode module 4 generates andoutputs to the host computer 5 the decoded data "2 MAIN street", andwhen the fixed, preprinted bar code 7B is scanned, the decode module 4generates the decoded data "TOWN, NY 12345" which is provided to thehost computer 5.

The reader 3 is also used to scan the hand-marked item selection line 9.Inthe above describe example, in the item selection line 9, only thePANTS segments 9B has its corresponding invisible bar 10B hand-marked.The invisible bars 10A and 10C are not hand-marked. It is noted that thehand-marked invisible bar 10B can be read by the reader 3 while theinvisible bars 10A and 10C which are not hand-marked can not be read bythe reader 3. Accordingly, the reader 3 will generate a digitized signalrepresentative of the three bar segments 9A-9C, where the digitizedsignalexcludes the invisible bars 10A and 10C which have not beenhand-marked, but includes the invisible bar 10B which has been handmarked. As can be appreciated, only the bar code segment 9B which hasthe hand-marked invisible bar 10B represents a valid Code 39 characterstring, and therefore, the decode module 4 properly decodes only barcode segment 9B and outputs the decoded data character "P" to the hostcomputer 5. The remaining two bar code segments 9A and 9C, which do notrepresent valid Code 39 character strings, are not properly decoded bythe decode module 4, and therefore, the decode module does not outputthe decoded data of bar code segments 9A and 9C to the host computer 5.

In a similar fashion, the reader 3 scans the color selection line 19.Assuming, for example, that the invisible bar 17C corresponding to thecolor GREEN is hand-marked. The decoder module 4 properly decodes thebar code segment 22C which includes invisible bar 17C and outputs thedecoded data character "G" to the host computer 5. Size selection line20 is also scanned by the reader 3. Assuming, for example, that theinvisible bar 18Dcorresponding to the size SIX is hand-marked. Thedecoder module 4 properlydecodes the bar code segment 23D which includesinvisible bar 18D and outputs the decoded data character "6" to the hostcomputer 5.

The user must be instruct to form hand-marked indications thatsubstantially correspond with the position of the invisible bar.However, it is noted that Code 39 is an extremely tolerant format, andreasonable deviations in the width of the hand-marked indications fromthe width of the invisible bar will not prevent proper decoding.

Readers 3 are generally arranged to read one single line of bar code ata time. For example, in the case where the reader 3 is a hand-held,trigger actuated, bar code reader, the operator of the reader 3 mustmanually aim the reader 3 at each of the selection lines 9, 19 and 20,and actuate the reader by pulling the trigger. However, it is possiblethat the operator could fail to properly scan one or more of theselection lines 9, 19 and 20.

Referring to the flow-chart of FIG. 4, the host computer 5 is arrangedto verify that each of the selection lines 9, 19 and 20 is scanned andto appropriately prompt an operator of the reader 3. It is first notedthat the character represented by each bar code segment 10A-10C, 22A-22Dand 23A-23E is unique (e.g., no two characters are the same). Theflow-chart starts at Step 40. At Step 41, an ITEM flag register, a COLORflag register, and a SIZE flag register are set. At Step 42, the hostcomputer 5 receives from the decoding module 4 the decoded characterwhich has beenscanned. At Steps 43, a check is made to determine whetherthe decode character received in Step 42 is one of the characters fromthe item selection line 9 (e.g., , "S" "P" or "D") and if yes, the ITEMflag is cleared in Step 46. Steps 44 and 45 check to determine whetherthe character received in Step 42 is a character from item selectionline 19 and 20, respectively, and if yes, the appropriate flag iscleared in Step 47 or 48. At Step 49, a check is made to determinewhether all the flags set in Step 41 are cleared, and if yes, it isdetermined that each of the selection lines 9, 19 and 20 have beenscanned and at Step 51 the host computer 5 displays on a display (notshown) information advising the operator that all selection lines havebeen scanned. If at Step 49, it is determined that some of the flags setin Step 41 remain set, at Step 50 the host computer 5 displays on thedisplay (not shown) information describing which of the selection lineshave not yet been read.

In FIG. 2, the user ordering section 8 contained a total of only twelvedifferent bar code segments 9A-9C, 22A-22D and 23A-23E, and therefore,it was possible provide a single unique character for each bar codesegment. However, if greater amounts of data are required to be enteredby a user, each bar code segment can contain a number of characters,where the sequence of the characters is unique for each bar codesegment.

Referring to FIG. 5, a document 60 for a multiple choice examination isshown. Bar codes 6, 7A and 7B, which are fixed, pre-printed codes thatcannot be modified by the user, are the same as those describe withreference to FIG. 2, and therefore, will not be further describedherein.

Answer rows 61.1-61.NN are printed on the document 60 where the firstanswer row is represented as 61.1 and the last answer row is representedas 61.NN. Referring for illustrative purposes to answer row 61.1, answerrow 61.1 includes pre-printed bar code segments 63A-63D, where each barcode segment is a string of encoded bar code characters, starting andending with the start/stop character "*". The alpha-numeric descriptionofthe sequence of characters for each of bar code segments 63A-63D isshown for illustrative purposes as 64A-64D, respectively. The characterstring for each of the bar code segments 63A-63D is "* nn y *" (where nn= question number 01-NN; y = answer A-D). For example, the characterstringsfor bar code segments 63A-63D are "*01A*", "*01B*", "*01C*" and"*01D*", respectively. The character strings for the bar code segmentsof the 15th answer row (not shown) are "*15A*", "*15B*", "*15C*" and"*15D*".

Each of the bar code segments 63A-63D include an invisible bar 62A-62D(e.g., printed in red ink). An answer description 65A-65D is printedundereach of the invisible bars 62A-62D. The user is instructed, foreach answerrow 61.1-61.NN, to hand-mark the invisible bar associatedwith the desired answer description 65A-65D. After the document 60 iscompleted, each answer row 61.1-61.NN is individually scanned by reader3, and for each answer row, only the bar code segment 63A-63D having itsinvisible bar 62A-62D hand-marked is decoded and the correspondingdecoded character string 64A-64D is output to the host computer 5. Sinceeach character string identifies which answer row 61.1-61.NN it isassociated with, it isnot required to sequentially scan the answer rows.Further, since the character string for each of the bar code segments isunique, the flow-chart of FIG. 4 can be easily modified to verify thateach of the answer rows 61.1-61.NN has been scanned.

FIG. 6 shows an embodiment in which each invisible bar described withreference to FIG. 5 is replaced with sets of parallel marks 71A-71D.FIG. 6 shows a single answer row 70 which could be used to replaceanswer row one 61.1 of FIG. 5. The first preprinted bar code sequence72A in the answer row 70 includes wide and narrow bars and spacesarranged to form the character string "*01A*". All the bars (narrow andwide) in the bar code sequence 72A are printed as a grey color, with theexception of one wide bar in the bar code sequence 72A, which is printedas a set of dark black parallel marks 71A. The bars of the code areprinted in a grey colorso as to direct the user's attention to theparallel marks surrounding the white spaces 75A-75D. For example, thebar code sequence 72A represents the character string "*01A*" and thelast wide bar in the "A" character isselected to be the single wide barin the bar code sequence 72A which is printed as a set of dark parallelmarks 71A.

FIG. 9A shows in greater detail the character "A" portion of the barcode sequence 72A. FIG. 9B illustrates, for reference purposes, thecharacter "A" printed in standard Code 39 format. It is to be noted thatthe first four bars (starting from the left side of the drawings) ofFIG. 9A and FIG. 9B are identical. The parallel marks 71A include bars74 and 73, having inner edges 741 and 731, and having outer edges 740and 730, respectively. It is noted that the position of the outer edges740 and 730correspond with the position of the outer edges of the fifthbar shown in FIG. 7B. The inner edges 741 and 731 are separated by awhite space 75A having a predetermined width X. The width X of the whitespace is intentionally selected to be large enough to prevent thedecoder 4 from successfully decoding the bar code sequence 72A.

When the reader 3 scans the pre-printed answer line 70, prior tohand-marking, a digitized signal representative of the answer line 70 isformed. The digitized signal includes an indication of the white space74A-74D between each set of parallel marks 71A-71D, respectively. Thedecoder 4 receives the digitized signal and fails to decode any of thebarcode segments 72A-72D as proper code 39 character strings due to thepresence of the white spaces 74A-74D. The user hand-marks the answerline 70 by filling in a selected one of the white spaces 75A-75D. Forexample, for the user to select multiple choice answer "A" the userhand-marks white space 75A corresponding to multiple choice answer "A".However, it is known that it is difficult for a user to maintain ahand-mark within a given boundary, such as the white space 75A. However,the bars 73 and 74 surrounding the white spaces act as guard bands whichthe user's hand-markcan inadvertently extend into without a negativeeffect on the decoding of the answer line 70. After a selected one ofthe white spaces 75A-75D is hand-marked, the answer line 70 can bescanned by reader 3 and the decoding module will output the characterstring corresponding to the bar code segment 72A-72D which includes thehand-marked white space 75A-75D, in a manner similar to that describedabove with reference to FIG. 5.

Alternatives to the red invisible bars and the parallel marks abovedescribed are envisioned in accordance with the present invention. Forexample, the invisible bars could be replaced with a very lightly shadedbar which is below the threshold detection of the reader 3. Further, anymarking which is visible to the human, but is below the thresholddetection of the reader 3 can be used in place of the red invisiblebars. The parallel marks could be replaced by three or more bars,provided that the decoder 4 fails to properly decode the character thatincludes the parallel marks. In fact, the parallel marks can be replacedby any patternthat causes the decoder 4 to fail to properly decode thecharacter that includes the respective pattern. Still further, theinvisible bars can replace one of the bars in the start/stop characteras opposed to replacing a bar in the character string.

FIG. 8 illustrates a further embodiment of the present invention. Insome applications, the hand-mark section (e.g., answer lines 61.1-61.NN)of thedocument 60 shown in FIG. 5 appears to a user as excessivelycomplex due tothe visibility of the bars and strips. FIG. 8 shows anopaque template sheet 90, which is removably placed over the answerlines 61.1-61.4 of thedocument shown in FIG. 5. The template sheet 90has cutout windows 91.1A-91.1D which are substantially the same size andshape as the invisible bars 62A-62D shown in FIG. 5, and are alignedsubstantially overthe invisible bars 62A-62D. Printed on the templatesheet 90, are an indication of the question number 93 and an indicationidentifying the possible multiple choice answers 92A-92D. Similar cutoutwindows and printing on the template sheet correspond to the answer rows61.2-61.NN.

As can be appreciated, the template sheet 90 includes only the printingthat is required to be visible to the user. The underlying bars andspacesare not visible to the user, thereby simplifying the appearance ofthe document.

To select an answer in answer row one 61.1, the user handmarks aselected one of the invisible bars 62A-62D, which is positioned undercutout windows 91.1A-91.1D, respectively. There is no requirement thatthe hand-marked indication be confined to the inside of the respectivecutout window, since any markings made outside of the selected cutoutwindow willbe drawn on the template sheet 90, and will not be marked onthe document. The remaining answer rows 61.2-61.NN are hand-marked in asimilar manner.

The template sheet 90 can be, for example, removably attached to thedocument by a weak adhesive that permits the template sheet 90 to beremoved without tearing or defacing the underlying document 60. To readthe document, an operator removes the template sheet 90 and utilizes thereader 3, decoder 4 and host computer 5 of FIG. 1 in a manner similar tothat described with reference to FIG. 5, to determine which answers havebeen handmarked by the user.

FIGS. 9a and 9b show front and side views of a further embodiment of thepresent invention in which the template sheet 90 of FIG. 8 is replacedwith overlay sheet 95. Overlay sheet 95 is a opaque removable sheethavingno cutout windows. On the underside of the overlay sheet 95, ateach position which corresponds to the invisible bars 62A-62D of answerrow one61.1, there are located transfer indications 94.1A-94.1D, each ofwhich canbe transferred from the overlay sheet 95 to the document 60when sufficientpressure is applied to the top side 95T of overlay sheet95. Each of the transfer indications 94.1A-94.1D have a shapesubstantially similar to theinvisible bars and each is positioneddirectly over a corresponding invisible bar. On the top side 95T of theoverlay sheet 95 there is printed an indication of the question number93, an indication identifyingthe possible multiple choice answers92A-92D for each question, and location boxes 96A--6D corresponding tothe position of the transfer indications 94.1A-94.1D.

To select an answer in answer row one 61.1, the user handmarks aselected one of the location boxes 96A-96D with a writing instrument,such as a penor pencil. The pressure from the pen or pencil causes thecorresponding transfer indication 94.1A-94.1D to be transferred onto thecorresponding invisible bar location on the document. The user is notrequired to remainstrictly within the bounds of the selected locationbox, since there is no transfer indication outside of the position ofthe location boxes. Accordingly, hand-marks made on the top side 95T ofthe overlay sheet which are outside of the location boxes 96A-96D arenot reflected on the actual document. In this way, very messy handmarkscan be tolerated.

After all the questions are answered, the overlay sheet 95 can beremoved and the reader 3, decoding module 4 and the host computer 5 usedin a manner similar to that described with reference to FIG. 6 todetermine which answers have been selected.

The transfer indications 94.1A-94.1D can be, for example, carbon typeink, similar to that used in standard carbon paper, which is preprintedon the underside 95U of the overlay sheet 95. The pressure generated bythe hand-marking on the top side 95T of the overlay sheet cause aportion of the carbon ink to be transferred to the document.Alternatively the transfer indications can be a type of stencil that istransferred from theoverlay sheet 95 to the document when acorresponding area on the top side 95T of the overlay sheet 95 ishand-marked.

FIGS. 10 and 11 illustrate a further embodiment of the presentinvention. Referring to FIG. 10, answer row one 61.1, which includes barcode segments 100A-100D is preprinted. In this embodiment each bar codesegment, as preprinted, can be read and decoded without requiringhand-marking. Referring to bar code segment 100A, it begins and endswith a bar code representing the start/stop character "*". Thecharacters between the start/stop character identify the question number(e.g., "01")and identify the answer (e.g., "A"). Below each bar codesegment 100A-100D is printed an indication of the possible multiplechoice selections 101A-101D.

Referring to FIG. 11, the user selects the multiple choice answer byplacing a hand-marked indication 105 over a portion of the bar codesegment 100A-100D which corresponds to the desired multiple choiceselection. In this way, the bar code segment corresponding to thedesired multiple choice selection is rendered non-decodable. Thehand-marked 105 indication does not have to be well formed and does nothave to be of a predetermined shape. Provided that the hand-markindication completely covers at least one of the spaces in the bar codesegment, the segment will be rendered unreadable.

The reader 3, the decoding module 4 and the host computer 5 shown inFIG. 1can be used to determine which of the multiple choice selectionsshown in FIG. 11 have been hand-marked. At the outset, it is noted thatmost decoding modules 4 arranged for reading standard formats, such asCode 39,will only output the characters associated with the first validbar code segment 100A-100D encountered. However, many of the knowndecoding modulesare software based, and the software in the decoder canbe modified to cause the reader to output all the valid bar codesegments 100A-100D encountered in an answer row 61.1.

The reader 3 scans the answer row 61.1 and provides a digitized signalrepresenting the answer row to the modified decoding module 4. Thedecoding module decodes the digitized signal and outputs the charactersofeach valid bar code segments encountered to the host computer 5. Forexample, if the user handmarked 105 the bar code segment 100Acorresponding to multiple choice selection "A" the decoding module 4will not be able to decode bar code segment 100A but will decode barcode segments 100B-100D. Accordingly, the decoding module 4 will outputcharacter strings "01B", "01C" and "01D" to the host computer 5. Thehost computer 5 can be programmed to store the character string thatrepresentseach of the bar code segments 100A-100D of each answer row(e.g., possible character strings for answer row one are "01A", "01B","01C" and "01D"). Accordingly, upon receiving the character strings fromthe decoding module4, the host computer 5, by process of elimination,determines which of the bar code segments has been hand-marked.

FIGS. 12 and 13 illustrate a further embodiment of the presentinvention. In this embodiment, answer row 110 is a pre-printed bar codehaving a string of encoded characters positioned between one set ofencoded start/stop characters "*" 111. In the example shown, thecharacters "ABCDE" are positioned between the start/stop characters 111.Printed in red-ink over a portion of each character is a location box110A-110E. Answer row 110 can be read and decoded using a standard Code39 reader 3 and decoding module 4 provided that none of the locationboxes are hand-marked.

Referring to FIG. 13, the user selects a desired multiple choice answerby placing a hand-marked 112 indication over a portion of a selected oneof the location boxes 110A-110E, each of which corresponds to adifferent multiple choice answer. In this way, the bar code charactercorresponding to the desired multiple choice selection is renderednon-decodable.

The reader 3, the decoding module 4 and the host computer 5 shown inFIG. 1can be used to determine which of the multiple choice selectionshave been hand-marked. At the outset, it is noted that most decodingmodules 4 arranged for reading standard formats, such as Code 39, willnot output any of the characters within a bar code segment if one ormore of the characters within the bar code segment is not decodable.However, many of the known decoding modules are software based, and thesoftware in the decoder can be modified to cause the reader to outputall the valid characters encountered in an answer row 110, even if oneor more of the characters encountered are invalid.

The reader 3 scans the answer row 110 and provides a digitized signalrepresenting the answer row to the modified decoding module 4. Thedecoding module decodes the digitized signal and outputs the validcharacters of answer row 110 to the host computer 5. For example, if theuser hand-marked 112 the location box 110A corresponding to multiplechoice selection "A", the decoding module 4 will not be able to decodethe "A" character but will decode the "B", "C", "D" and "E" character,and will output the "B", "C", "D" and "E" characters to the hostcomputer 5. The host computer 5 can be programmed to store datarepresenting all the characters of each answer row (e.g., possiblecharacters for answer row one is "A" "B", "C", "D" and "E").Accordingly, upon receiving the character strings from the decodingmodule 4, the host computer 5, by process of elimination, determineswhich of the bar code characters has been hand-marked.

FIG. 14 illustrates a further embodiment of the present invention. Inthis embodiment, answer row 120 is a pre-printed bar code having astring of encoded characters positioned between one set of encodedstart/stop characters "*" 121. In the example shown, the characters"01234567892" arepositioned between the start/stop characters 121. Thefirst ten characters (e.g., "0123456789") represent different possiblemultiple choice selections 123 and the eleventh character represents achecksum character 124 calculated in accordance with the Code 39standard (e.g., sum of numerical values which are assigned to each ofthe characters in the multiple choice selection 123 is taken, module 43.For example, assuming the numerical values assigned to each charactershown in FIG. 14 is as follows 0=0, 1=1, 2=2, 3=3, 4=4, 5=5, 6=6, 7=7,8=8, 9=9: 0+1+2+3+4+5+6+7+8+9=45; Checksum character = 45 Mod 43 = 2).Printed in red-ink over a portion of each of the first ten characters isa location box 120A-120J. Answer row 120 can be read and decoded using astandard Code 39 reader 3 and decoding module 4 provided that none ofthe location boxes 120A-120J are hand-marked.

The user selects a desired multiple choice selection by placing ahand-marked indication 122 over a portion of a selected one of thelocation boxes 120A-120J, each of which corresponds to a differentmultiple choice selection 123. In this way, the bar code charactercorresponding to the desired multiple choice selection is renderednon-decodable. For example, FIG. 14 shows that location box 120B, whichcorresponds to multiple choice selection "1" is hand-marked, andthereforethe "1" is rendered non-decodable.

The reader 3 and the decoding module 4 shown in FIG. 1 can be used todetermine the character that corresponds to the multiple choiceselection 123 hand-marked 122. At the outset, it is noted that mostdecoding modules4 which are arranged for reading standard formats, suchas Code 39 with checksum digit, will not output any of the characterswithin a bar code segment if the checksum calculated for the multiplechoice selections do not match the checksum digit, as is the case whereone of the multiple choice selections is hand-marked. However, many ofthe known decoding modules are software based. The software in thedecoder module 4 can be modified so that it decodes all the charactersof the answer row 120, including the checksum digit 124, with theexception of the one character which is hand-marked 122. The decoder 4then performs the operation shown in the flow-chart of FIG. 15, andoutputs to the computer 5 the identity of the one character which ishand-marked.

Referring to the flow-chart of FIG. 15, at Step 130, each of multiplechoice selections 123 is decoded by the decoding module 4, with theexception of the one multiple choice selection which is hand-marked 122,and the numerical value assigned to each of the multiple choiceselections123 decoded are summed and the result stored as variable NHM.The checksum digit 124 is also decoded and the numerical value assignedto the checksumcharacter is stored as variable CS.

At Step 140, the decoding module 4 determines the numerical value of thecharacter which is rendered unreadable by the handmarking. In moredetail,it is known that (NHM + HM) Mod 43 = CS, where HM equals thenumeric value associated with the hand-marked character. At Step 140 thedecoding module4 solves for HM.

Steps 140A-140E of FIG. 16 illustrates a method by which the decodingmodule 4 solves at Step 140 for HM. At Step 140A a loop counter (LOOP)is set equal to zero. At Step 140B, LOOP is incremented by one. At Step140C,the decoder 4 calculates ((43,LOOP) + CD - NHM) and stores theresult as X.At Step 140D, if X is greater than or equal to zero,progress is made to Step 140E where HM is set to equal X and the programreturns to Step 140 in FIG. 16. If at Step 140D, X is not greater thanor equal to zero, progress is made to Step 140B where loop 140B-140D isrepeated until X is found to be greater or equal to zero at Step 140D.

At Step 141 shown in FIG. 15, the decoder module 4 determines theidentity of the hand-marked character based upon the numerical value ofHM determined in Step 140, and outputs the identity of the hand-markedcharacter to the host computer 5.

For the specific example shown in FIG. 14, the sum of the multiplechoice selections "0123456789" 123 is "45" and therefore the checksumdigit equals (45 Mod 43) = "2". The multiple choice selection "1" ishand-marked122. Accordingly, referring to FIG. 16, at Step 130NHM=0+2+3+4+5+6+7+8+9=44. In FIG. 16, at Step 140B LOOP=1, and at Step140C X=(43*1)+2-44=1. At Step 140D, "1" is determined to be greater thanzero and at Step 140 HM is set equal to "1". At Step 141 in FIG. 16, aHM value of "1" is determined to correspond to the character "1" andtherefore, the character "1" is output to the host computer 5.

As can be appreciated in the above embodiment, the host computer 5receivesinformation identifying the hand-marked character. It is notrequired that the decoding module 4 or the host computer 5 bepre-programmed to store all the possible multiple choice selections 123.Accordingly, the embodiment described with reference to FIGS. 14-16 isextremely flexible and can be applied in a variety of applications.

While the above aspects of the present invention have been illustratedand described using bar codes conforming to the Code 39 standard, andusing laser bar code readers,, it is not intended that the presentinvention be limited to the details and applications shown, sincevariations and modifications and structural changes can be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can readily adapt it for variousapplications without omitting features that, from the standpoint ofprior art, fairly constitute essential characteristics of the generic orspecific aspects of this invention and, therefore, such adaptationsshouldand are intended to be comprehended within the meaning and rangeof equivalence of the following claims.

What is claimed is:
 1. A method of entering a hand-marked response intoa system using a plurality of encoded and pre-printed bar codesequences, each bar code sequence corresponding to a uniquepredetermined character string and including a plurality of spaces and aplurality of bars and a modified bar, the modified bar arranged torender the bar code sequence non-decodable by a bar code decoding devicewhen the modified bar is not hand-marked, the modified bar arranged torender the bar code sequence decodable by the bar code decoding devicewhen the modified bar is hand-marked, the method comprising;a)hand-marking the modified bar of a selected one of the plurality of barcode sequences; b) reading the plurality of bar code sequences with abar code reading means and forming a first signal representative of theplurality of bar code sequences; c) processing the first signal with thebar code decoding device to decode said unique predetermined characterstring corresponding to the selected one of the plurality of bar codesequences which includes the hand-marked modified bar, and forming asecond signal including the decoded unique predetermined characterstring of the selected one of the plurality of bar code sequences; andd) outputting the second signal from the bar code decoding device to thesystem.
 2. The method in accordance with claim 1 wherein the bars of theplurality of bar code sequences are a first color and the modified barof each of the plurality of bar code sequences is a second color,wherein the first color can be read by bar code reading means and thesecond color can not be read by the bar code reading means, and whereinthe step of hand-marking includes the step of changing the second colorof the modified bar.
 3. The method in accordance with claim 1 whereinthe modified bar includes a plurality of guide bars separated by apredetermined space, and wherein the step of hand-marking includes thestep of darkening the predetermined space.
 4. The method in accordancewith claim 1 in which the step of hand-marking the modified bar of theselected one of the plurality of bar code sequences includes the step ofguiding a hand-marking device over the selected modified bar with atemplate means, said template means being removable affixed on top ofthe plurality of bar code sequences and having a plurality of openings,each of the plurality of openings being aligned with the position of themodified bars.
 5. The method in accordance with claim 4 in which thestep of reading the plurality of bar code sequences includes the step ofremoving the template means affixed to the top of the plurality of barcode sequences.
 6. The method in accordance with claim 5 wherein themodified bar is a space.
 7. The method in accordance with claim 1wherein an overlay means having a plurality of transfer indication meansis removably affixed on top of the plurality of bar code sequences, theposition of each one of the plurality of transfer indication meansaligned with the position of one of the modified bars, and wherein thestep of hand-marking the modified bar of the selected one of theplurality of bar code sequences includes the step of transferring fromthe overlay means to the modified bar at least a portion of the transferindication means aligned with the position of the modified bar of theselected one of the plurality of bar code sequences.
 8. The method inaccordance with claim 7 wherein the step of transferring includes thestep of applying pressure to the overlay means at a positionsubstantially corresponding to the modified bar of the selected bar codesequence.
 9. The method in accordance with claim 8 in which the step ofreading the plurality of bar code sequences includes the step ofremoving the overlay means affixed to the top of the plurality of barcode sequences.
 10. A method of entering a hand-marked response into asystem by hand-marking at least one of a plurality of encoded andpreprinted bar code sequences, each bar code sequence corresponding to aunique predetermined character string, where a bar code decoding deviceis used for decoding the unique predetermined character string of eachof the bar code sequences which is not hand-marked, and where the barcode decoding device fails to decode the bar code sequence of each ofthe bar code sequences which is hand-marked, the method comprising;a)storing the unique predetermined character strings corresponding to eachof the plurality of bar code sequences in a memory; b) hand-marking atleast one of the plurality of bar code sequences; c) reading theplurality of bar code sequences with a bar code reading means andforming a first signal representative of the plurality of bar codesequences; d) processing the first signal with the bar code decodingdevice to decode each of said unique predetermined character stringswhich correspond to the plurality of bar codes sequences other than thehand-marked bar code sequences, and forming a second signal representingthe decoded unique predetermined character strings which correspond tothe plurality of bar codes sequences other than the hand-marked bar codesequences; and e) comparing the unique predetermined character stringsrepresented in the second signal against the contents of the memory, andbased on the comparison, forming a third signal representing the uniquepredetermined characters which are contained in the memory but are notrepresented in the second signal.
 11. The method in accordance withclaim 10 wherein each of the plurality of bar code sequences includes aplurality of bars and a plurality of spaces, and wherein the step ofhand-marking at least one of the plurality of the bar code sequencesincludes the step of darkening substantially all of at least one of theplurality of spaces of the selected bar code sequences.
 12. A method ofentering a hand-marked response into a system by hand-marking at leastone character selected from a plurality of characters in a bar codesequence, where a bar code decoding device is used for decoding eachcharacter of the plurality of characters which is not hand-marked, andwhere the bar code decoding device fails to decode each hand-markedcharacter selected from the plurality of characters, the methodcomprising;a) storing each of the plurality of characters of the barcode sequence in a memory; b) hand-marking at least one characterselected from the plurality of characters of the bar code sequence; c)reading the bar code sequence with a bar code reading means and forminga first signal representative of the bar code sequence; d) processingthe first signal with the bar code decoding device to decode each ofsaid plurality of characters other than the at least one hand-markedcharacter, and forming a second signal representing each of the decodedcharacters other than the handmarked characters; and e) comparing thecharacters represented by the second signal against the contents of thememory, and based on the comparison, forming a third signal representingthe characters which are contained in the memory but are not representedby the second signal.
 13. A method of entering a hand-marked responseinto a system by hand-marking a selected character from a plurality ofdata characters in a bar code sequence, the bar code sequence includinga checksum character which is a function of the plurality of datacharacters, where a bar code decoding device is used for decoding thechecksum character and each data character of the plurality ofcharacters which is not hand-marked, and where the bar code decodingdevice fails to decode the hand-marked character selected from theplurality of characters, the method comprising;b) hand-marking onecharacter selected from the plurality of characters of the bar codesequence; b) reading the bar code sequence with a bar code reading meansand forming a first signal representative of the bar code sequence; c)processing the first signal with the bar code decoding device to decodethe checksum character and to decode each of said plurality of datacharacters other than the hand-marked character, and forming a secondsignal representing the checksum character and the decoded characterswhich correspond to the plurality of data characters other than thehand-marked character; and d) processing the second signal to determinethe value of the hand-marked character based upon the decoded checksumcharacter and the decoded plurality of data characters other than thehandmarked character, and forming a third signal representing thehandmarked character.